1. The Field of the Invention
The present invention relates to a wheel for vehicles and in particular to a vehicle wheel comprising a disc and a rim made from sheet metal, which is assembled under the outer rim seat.
2. The Related Art
Patent EP 0 464 449 relates to a wheel comprising a sheet metal rim with an outer and an inner rim flange, an outer rim seat with a radially outer frustoconical wall and an inner rim seat, a mounting groove, a disc with a hub bearing surface, a radially outer edge designed for assembly with the rim, and a connection zone, the assembly between the rim and the disc being carried out between the radially inner wall of the outer rim seat and the radially outer wall of the edge of the disc. The connection between the disc and the rim consists of a continuous weld bead between the disc and the rim on the axially outer side, and such that the weld bead has undergone a finishing operation by removal of material so that the surface condition of the weld bead ensures visual continuity of shape between the disc and the rim. The visual impression produced by such a wheel is similar to that of a “full-face” wheel, in which the disc is continuous as far as the outer rim flange of the rim. Such a full face wheel is shown, for example, in FIG. 11 of WO 99/33594.
The assembly between the disc and rim of such a wheel is carried out by fitting together two conical zones: the radially inner wall of the outer rim seat and the radially outer wall of the disc's assembly edge. To ensure good strength of the joint between the disc and the rim, it is important to control the tightening force between the disc and the rim. “Tightening force” means the complex of forces developed between the touching portions of the disc and rim during fitting, which are due to the varying diameters of the two walls in contact.
Since this assembly is carried out between conical components, tightening is a direct function of the amount by which the rim is off-center, i.e., the distance between the axial position of the median plane of the rim and the bearing surface of the disc. Consequently, conical fitting makes it complicated to control the amount by which the wheel is off-center and the degree of tightening, both at the same time and under industrial manufacturing conditions.